Biomaterial Database

Virulence profiles and antibiotic susceptibility patterns of Klebsiella pneumoniae strains isolated from different clinical specimens. 2013

R El Fertas-Aissani, and Y Messai, and S Alouache, and R Bakour

Laboratoire de biologie cellulaire et moléculaire, faculté des sciences biologiques, université des sciences et de la technologie Houari Boumediene, BP 32 El-Alia, Bab Ezzouar, 16111 Alger, Algeria.

OBJECTIVE To detect virulence factors in 54 Klebsiella pneumoniae isolates from different clinical specimens: urine (26), blood (11), pus (11), lung (four), cerebrospinal fluid (one) and ascitic fluid (one). METHODS PCR was used to investigate virulence genes encoding adhesins (fimH-1, mrkD, kpn, ycfM), siderophores (entB: enterobactin, iutA: aerobactin, irp-1, irp-2, ybtS, fyuA: yersiniabactin, iroN: catechols receptor), protectines or invasins (rmpA, magA, traT) and toxins (hlyA, cnf-1). The serum resistance, capsule and hypermucoviscosity, and ability to form biofilm and produce siderophores were sought by phenotypic assays. The in vivo virulence was assessed in mice infected by intraperitoneal way. Antimicrobial susceptibility was tested by diffusion method. RESULTS The most common virulence genes were fimH-1 (100%), mrkD (96.3%), ycfM (96.3%), and entB (100%). kpn and yersiniabactin genes were found at medium rates of 63% and 46.3% and at lower prevalence, were genes traT (1.8%), iroN (3.7%), iutA (5.5%) and rmpA (3.7%). magA, hlyA and cnf-1 genes were not detected. The capsule, serum resistance, biofilm formation, mannose-sensitive or -resistant haemagglutination and hypermucoviscosity were observed in 100%, 92.6%, 88.8%, 94.4%, 68.5% and 9.2% of isolates, respectively. The prevalence of siderophores was consistent with that of genotypic detection. The LD50 in mice was very low (<10(2) CFUs) for isolates with the most virulence factors. A rate of 74.1% of isolates showed a multidrug resistance (MDR) pattern. CONCLUSIONS The distribution of virulence profiles according to the clinical origin suggests a role of enterobactin in urinary infections and yersiniabactin in the invasiveness. The fimbriae F1 and F3, capsule, enterobactin, serum resistance and biofilm formation, were commonly found in isolates, they seem to be at the basis of classic pathogenicity of K. pneumoniae. The invasiveness enhancers, aerobactin, yersiniabactin, catechols receptor, mucoid factor and hypermucoviscosity, detected concomitantly in some isolates, constitute a threat for vulnerable populations, even more if they are in combination with antibiotic resistance.

UI	MeSH Term	Description	Entries
D007711	Klebsiella pneumoniae	Gram-negative, non-motile, capsulated, gas-producing rods found widely in nature and associated with urinary and respiratory infections in humans.	Bacillus pneumoniae,Bacterium pneumoniae crouposae,Hyalococcus pneumoniae,Klebsiella pneumoniae aerogenes,Klebsiella rhinoscleromatis
D007928	Lethal Dose 50	The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.	LD50,Dose 50, Lethal
D008826	Microbial Sensitivity Tests	Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).	Bacterial Sensitivity Tests,Drug Sensitivity Assay, Microbial,Minimum Inhibitory Concentration,Antibacterial Susceptibility Breakpoint Determination,Antibiogram,Antimicrobial Susceptibility Breakpoint Determination,Bacterial Sensitivity Test,Breakpoint Determination, Antibacterial Susceptibility,Breakpoint Determination, Antimicrobial Susceptibility,Fungal Drug Sensitivity Tests,Fungus Drug Sensitivity Tests,Sensitivity Test, Bacterial,Sensitivity Tests, Bacterial,Test, Bacterial Sensitivity,Tests, Bacterial Sensitivity,Viral Drug Sensitivity Tests,Virus Drug Sensitivity Tests,Antibiograms,Concentration, Minimum Inhibitory,Concentrations, Minimum Inhibitory,Inhibitory Concentration, Minimum,Inhibitory Concentrations, Minimum,Microbial Sensitivity Test,Minimum Inhibitory Concentrations,Sensitivity Test, Microbial,Sensitivity Tests, Microbial,Test, Microbial Sensitivity,Tests, Microbial Sensitivity
D006761	Hospitals	Institutions with an organized medical staff which provide medical care to patients.	Hospital
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000462	Algeria	A country in northern Africa bordering the Mediterranean Sea, between MOROCCO and TUNISIA. Its capital is Algiers.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D016133	Polymerase Chain Reaction	In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.	Anchored PCR,Inverse PCR,Nested PCR,PCR,Anchored Polymerase Chain Reaction,Inverse Polymerase Chain Reaction,Nested Polymerase Chain Reaction,PCR, Anchored,PCR, Inverse,PCR, Nested,Polymerase Chain Reactions,Reaction, Polymerase Chain,Reactions, Polymerase Chain
D017262	Siderophores	Low-molecular-weight compounds produced by microorganisms that aid in the transport and sequestration of ferric iron. (The Encyclopedia of Molecular Biology, 1994)	Siderophore,Siderochromes
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus